Electropneumatic air-brake system.



G. MACLOSKIE. ELEGTROPNEUMATIGKAIR BRAKE SYSTEM.

APPLIQATION FILED FEB. 1,1910.

Patented May 10, 1910.

/n Vento/f' Geolye UNITED sTA'rus rArEN'r OFFICE.

GEORGE MAGLOBKIE, OF SCHENEOTADY, NEW YORK, ASBIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTBDPNEUMATIG AIR-BRAKE SYSTEM.

specification of Letters Eatent.

Patented May 10, 1910.

To all whom 'it may concern.:

Be it known that I, GEORGE Maolpsnls, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Electropneumatic Air-Brake Systems, of which the following is a specification.

My invention relates to air brake systems in which the application and release of the brakes are electrleally controlled, and 1ts ob- 'ect is to provide a novel arrangement of the valves and controlling means therefor such thatthc brake cylinder pressures on all the cars of a train will be substantially equal at all times regardless of differences in the travels of the brake cylinder pistons, and small leakages from brake cylinders will be automatically provided for.

My invention consists in providing l a valve mechanism for controlling the adunasion of air to, and exhaust from, the brake c linder, controlled jointly by brake cyliner pressure and by a second preure the amount of which is varied by the electromagnetic control apparatus.

My invention wlll best be understood by reference to the accompanying drawing in which,

Figure 1 shows da rammatically an air brake system arrange in accordance with my invention; Fi 2 shows a view, partly in cross-section, o the electropneumatically operated valves; and Fig. 3 shows a crosssectional view ci' the valve controlled there-- by for admitting air to, and releasing it from, the bra-ke cylinder.

have shown my invention applied to a combined pneumatic and electric brake sysu tem, the pneumatic system comprising the usual tram pipe triple valves and motormans valve, and the electric system coinprising suitable electromagnetically operated valve mechanism, the two systems being connected alternately to brake cylinder as one or the other is used by a double throw check valve. A. system of this type is shown in my prior Patent, No. 869,444, dated Oc toher 29, 1907.

In the drawing, A represents the air compressor and B the main reservoir charged thereby and connected through a suitable reducin or feed valve b to a train pipe C to whic' the motormans valves are connected on one side. These valves, on the other side, are connected to the train pipe D to which the triple valves are connected.

E E are the motormans valves; F the tri le valve, and Gr the brake cylinder.

re resents the double throw check valve by which the pneumatic or electric valve mechanism, according as one or the other is used, is connected to the brake cylinder in the same manner as in my prior patent. above referred to.

The electric system, in which my present invention resides, includes switch contacts I I under the control of the motorman, a pair of train wires J, either of which may be energized by the switch contacts I, and a pair of magnets K and K controlling the electric. application and release of the brakes, respectively. When the switch contacts I I are in the position shown, neither train wire J and, consequently, neither ma net K or K', is energized. By moving e switch contact one direction or the other, one magnet or the other is energized.

W'ith the particular arrangement of valves shown in Fig. 2 when neither magnet is energized the valves are in the lap position. Then magnet K is energized air is admitted to the brake cylinder and when magnet K' is energized air is exhausted from the brake cylinder. The valve mechanism by which these results are obtained is shown in 2 and 3. In Fig. 2, L and L represent pupv pet valves which are normally held seated by light springs and which are opened, respectively, when the magnets K and K are energized so as to pull down their plungers. The valve casing has three pipe connections; one o leading to the train pipe C; another cz opening to atmosphere, and third m which is connected to what may be termed a regulating reservoir M. This pipe m extends also into u valve casin N in which is a slide valve 0 controlled i5' a. piston l and a puppet valve Q which is normally held seatcd by a light spring but which is adapted to be enga ed and uns-cated by the rod of piston l. his valve casing has four pi Je connections; one m on one side of piston another lo connected through the double throw check vulve H to brake cylinder G; a third, c connected to the control pi ie, and a fourth, c opening to atmos here. uring the electric operation of the rulrcs, pipe la is connected to brake cylinder, so that piston I is sub'eeted to the opposing rssures of brake cy iiider and of the regu ating resorvoir M.

When the magnets K and K are bolli deenergized and puppet valves L and L both closed, piston P and slide valve O are in the position shown in Fig. 3. In this position, both the slide valve O and puppet valve Q are closed, so that the valve mechanism is in lap position To admit air to the brake cylinder by means of the electric control, switch I is moved so as to energize the lower control wire J, thereb energizing magnet K. This magnet pu s down its plunger, opening puppet valve L and connecting the contro pipe through pipe connections c and m to the regulating reservoir M. The pressure in this reservoir, consequently, rises by an amount determined by the length of time that magnet K is kept energized. The increased pressure in the regulating reservoir is impressed on one side of piston P through pipe m so that the piston rod is moved back so as to open puppet valve Q. Air is then admitted from control pipe C, through pipe connections c, valve Q and pipe connection It to the brake cylinder G. Air continues to flow into the brake cylinder until the pressure in the brake cylinder equals that in the regulating reservoir N; when pressures on opposite sides of piston l? are balanced and the piston moves back allowing valve Q to be seated by its spring. For a partial release of the brakes, magnet K is energized long enough to release a portion of the air from the re ulating reservoir M through valve L. T e reduction of air in reservoir M and, consequently, on the lower side of piston P, causes this piston to move so as to open the port leading to atmosphere at a. Air, consequently, flows from brake cylinder through pipe connections li, and a to atmosphere and the exhaust continues until the pressure in the brake e linder falls to an amount equal to or slig tly below that in the regulating reservoir, when the piston P moves back, causing slide valve O to close the exhaust. For a complete release of the brakes, magnet K is kept energized until the air is entirely exhausted from reservoir M, in which case slide valve O remains open and all the air is exhausted from the brake cylinder.

If all the regulating reservoirs M on all the cars of the train are of the same size and the magnet valves on all the cars nre of the same construction, the pressures on all the regulating reservoirs wi l always be the same on all the cars, since all the magnet valves are simultaneously actuated; therefore, the brake cylinder pressures on all the cars will be equal, since these pressures always correspond to llio pressure in the regulating reservoirs. Furthermore, if wliilc tlic brake valves nrc iii lap position willi the brakes applied, pressure should leuk from a brake cy iiidei, the piston P will operate to open va ve Q and supply suiiicient air to the brake cylinder to compensate for the lealr und to maintain the ressure.

I do not desire to imit mysclf to the particular construction and arrangement of parts shown and described, but aim in the appended claims to cover all modifications which are within the scope of my invention.

What I claim as new and desire to .secure by Letters Patent of the United States, is,"

1. In an air-brake system, in combination with the brake cylinder and a source of pressure therefor, a r lating reservoir, valve mechanism for a itt-ing air from said source to, and exhausting air from, said reigulating reservoir, electromagnetic means or operatin said vulve mechanism, valve mechanism n' admitting air from said source to, and exhausting air from, the brake cylinder, and o erating means therefor controlled jointly y the pressures in the brake cylinder and in said regulating reservoir.

2. In an air brake system, in combination with the brake cylinder and a source of pressure therefor, valve mechanism for admittingair from said source to, and exhausting air from, the brake cylinder, operating means therefor controlled jointly by brake cylinder pressure and a second pressure, and electroma etc means for varying the amount o said second pressure.

3. In an air brake system, in combination with the brake cylinder and a source of pressure therefor, valve mechanism for admitting air from said source to, and exhausting air from, the brake cylinder, operating means therefor comprising a movable inember subjected on one side to brake cylinder pressure, and electromagnetic means for producing a variable pressure on the opposite side of said member.

4. In an air brake system, in combination with the brake cylinder and a source of pressure therefor, a regulating reservoir, two valves for respectively admitting air from said source to, and exhausting air from, said regulating reservoir, a pair of electromagnets and control circuits therefor for oper- :itin said valves, valve mechanism for admitting air from said source to, and exhausting air from, said brake cylinder, and operating means therefor comprising a movn le member subjected to the opposing pressures in the brake cylinder and in said regulatin reservoir.

5. n an air brake system, in combination with the brake cylinder and a source of pressure therefor, a regulating reservoir, valve mechanism for admitting ur from said pressures in the brake cylinder und in Huid source to, and exhausting uit from, Suid reg regulating reservoir. 1o uluting reservoir, eltlonmgl'iete menus for In witness whereof, I lmvo hereunto set operating Suid vulve mechanism, vulve lnecl'imy hand this 31st (luy of January, 1910.

5 :mism for admitting air from said source to, GEORGE MACLOSKIE.

and'exhausting air from, the brake cylinder, Vifitnesses: and operating means therefor comprising n BENJAMIN B. HULL, movable member subjected to the opposing HELEN OnFoRD. 

